1. Field of the Invention
The present invention generally relates to hinge structures and, more particularly, to a hinge structure for use in an operation panel, for example, that is pivotally fixed to a portable electronic device, such as a memory card device or the like, which serves as an auxiliary storage device, for an information apparatus.
2. Description of the Related Art
A conventional portable electronic device, such as a memory card device for example, or a sub-unit is used by being inserted into a main unit of an information apparatus, such as an entertainment system, of which a typical example is a video game machine. Such a portable electronic device or a sub-unit of the information apparatus has an interface for connecting the device or the sub-unit to the main unit of the information apparatus and a non-volatile storage device for storing data.
FIG. 1A illustrates the configuration of the main portion of a memory card device, which serves as an example of conventional portable electronic devices. A memory card generally indicated by 10 includes a control unit 11 for controlling the operation of the memory card 10, a connector 12 used for connecting the memory card 10 to a terminal provided for a slot of the main unit, such as an information apparatus, and a non-volatile memory 16 for storing data. The connector 12 and the non-volatile memory 16 are connected to the control unit 11.
The control unit 11 may be formed of a microcomputer. As the non-volatile memory 16, a flash memory, such as an electrically erasable programmable read-only memory (EEPROM) may be used. As an interface for connecting the memory card 10 to the information apparatus, a microcomputer, which serves as a controller for interpreting protocols, may be used.
FIG. 1B illustrates items to be controlled by the control unit 11 of the memory card 10. FIG. 1B shows that the control unit 11 of the conventional memory card 10 includes only a main-unit-connecting interface for connecting the memory card 10 to the main unit, such as the information apparatus, and a memory interface for inputting and outputting data into and from the non-volatile memory 16.
Conventional video game machines, such as home-use TV game machines, have a function of storing game data into auxiliary storage devices. The above-described memory card device is also used as such an auxiliary storage device of the video game machine.
Referring to the schematic diagram illustrating an example of conventional video game machines using a memory card as an auxiliary storage device shown in FIG. 2, a main unit 2 of a conventional video game machine generally represented by 1 is accommodated within a generally quadrilateral housing. A disk-loading portion 3 is disposed at the center of the main unit 2 so as to load an optical disc, which is a recording medium for recording an application program, such as a video game. The main unit 2 also includes a reset switch 4 for resetting the game at any time, a power-supply switch 5, a disc operating switch 6 for operating the loading of the optical disc, and two slots 7A and 7B.
The memory card 10, which serves as an auxiliary storage device, is inserted into one of the slots 7A and 7B, and, for example, a game result obtained by executing the game on the video game machine 1 is sent from a control unit (central processing unit (CPU)) 19 and is written into the non-volatile memory 16. A plurality of operation units (controllers) (not shown) may be connected to the slots 7A and 7B, so that a plurality of users can simultaneously play an opposing game.
Hitherto, in the aforementioned conventional portable electronic devices, as shown in FIG. 3, an operation panel 203 may be pivotally fixed to a main unit 201 of the device via a hinge unit 202.
The hinge unit 202 is configured, as illustrated in FIG. 4, in such a manner that a shaft 205 projects from a casing 204, the shaft 205 being formed in a non-circular shape, as shown in FIG. 5. The hinge unit 202 is rotatable by a support component (not shown) built into the casing 204, and is stopped rotating every 180 degrees by an urging force of a spring (not shown) which is also built into the casing 204.
The above-configured hinge unit 202 is fixed at a predetermined position of the main unit 201 of the portable electronic device, as illustrated in FIG. 6, and the operation panel 203 is fitted to the shaft 205.
However, a large space is required for the above type of hinge unit 202 since the support component and the spring are built into the casing 204, thereby hampering the miniaturization of the hinge unit 202 and the saving of space. It is also difficult to detach the operation panel 203 from the main unit 201 of the electronic device. Additionally, if an excessive force is applied to the operation panel 203, not only the operation panel 203, but also the main unit 201 of the electronic device may be destroyed.
Accordingly, in order to solve the above-described problems, it is an object of the present invention to provide a simple and compact hinge structure which allows a movable portion to be easily attached to and detached from a main unit of a device and which prevents the movable portion and the main unit of the device from being destroyed even if an excessive force is applied to such movable unit.
In order to achieve the above object, according to the present invention, there is provided a hinge structure for pivotally and detachably fixing a movable unit to a main unit. The hinge structure of the invention preferably includes a shaft provided for one of the movable unit and the main unit, and a bearing unit provided for the one of the movable unit and the main unit that is not provided with the shaft. The bearing unit includes an opening for attaching or detaching the shaft in an axial direction. The bearing unit includes a first bearing for receiving one portion of a peripheral surface of the shaft and a second bearing for receiving another portion of the peripheral surface of the shaft, the first bearing and the second bearing facing or positioned adjacent each other. A space formed between the first bearing and the second bearing becomes narrower as it is closer to the opening, and at least one of the first bearing and the second bearing is formed of an elastic member.
The surface of the first bearing for receiving the shaft may preferably be formed in an arch-like shape, and the first bearing may preferably be formed of a non-elastic member provided for or formed from the main unit.
The surface of the second bearing for receiving the shaft may preferably be planar in shape, and the second bearing may preferably be formed of an elastic member, such as, for example, a leaf spring, provided for the main unit.
The shaft may preferably include a surface and a cam-like projection provided at part of the surface. The projection may preferably be located on the surface of the shaft at a position at which the bearing unit elastically slides over the cam-like projection while the movable unit is pivoting, in particular, while the movable unit is pivoting between a rising (open) state and a lying (closed) state.
The movable unit may preferably include an engaging portion to be engaged with part of the main unit when the movable unit is in a lying state. The engaging portion may preferably be configured to displace the movable unit in a direction in which a space between the first bearing and the second bearing widens against an elastic force while the engaging portion is engaged or is being engaged. The engaging portion may preferably include an engaging projection which slides over part of the main unit.
The opening may preferably widen due to an elastic deformation of the elastic member when attaching or detaching the shaft.
With the above arrangement, when an excessive force is applied to the movable unit or the main unit, the space between the first bearing and the second bearing widens by the shaft against an elastic force of the elastic member, thereby releasing the shaft from the bearing.